/*
 * This file is part of Zql.
 *
 * Zql is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Zql is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Zql.  If not, see <http://www.gnu.org/licenses/>.
 */

package Zql;

import java.util.Vector;

/**
 * ZGroupBy: an SQL GROUP BY...HAVING clause
 */
public class ZGroupBy implements java.io.Serializable {

	private static final long serialVersionUID = 3302030016639421088L;

	Vector<ZExp> groupby_;

	ZExp having_ = null;

	/**
	 * Create a GROUP BY given a set of Expressions
	 *
	 * @param exps
	 *            A vector of SQL Expressions (ZExp objects).
	 */
	public ZGroupBy(Vector<ZExp> exps) {
		groupby_ = exps;
	}

	/**
	 * Initialize the HAVING part of the GROUP BY
	 *
	 * @param e
	 *            An SQL Expression (the HAVING clause)
	 */
	public void setHaving(ZExp e) {
		having_ = e;
	}

	/**
	 * Get the GROUP BY expressions
	 *
	 * @return A vector of SQL Expressions (ZExp objects)
	 */
	public Vector<ZExp> getGroupBy() {
		return groupby_;
	}

	/**
	 * Get the HAVING clause
	 *
	 * @return An SQL expression
	 */
	public ZExp getHaving() {
		return having_;
	}

	@Override
	public String toString() {
		StringBuffer buf = new StringBuffer("group by ");

		// buf.append(groupby_.toString());
		buf.append(groupby_.elementAt(0).toString());
		for (int i = 1; i < groupby_.size(); i++) {
			buf.append(", " + groupby_.elementAt(i).toString());
		}
		if (having_ != null) {
			buf.append(" having " + having_.toString());
		}
		return buf.toString();
	}
};
